[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"notifications-list":3,"$f6wjd1m9c1izx":5},{"data":4},[],{"data":6,"error":11},{"id":7,"documentId":8,"slug":9,"name":10,"proprietary_name":11,"non_proprietary_name":11,"is_proprietary":11,"active_ingredient":10,"administration_route":11,"available_strength":11,"dosage_form":11,"dose_schedule":11,"drug_unit":11,"is_available_generically":11,"mechanism_of_action":11,"overdosage":11,"warning":11,"species":12,"citations":14,"dose_schedules":21,"available_strengths":41,"label_statements":56,"drug_classes":111,"specialties":117,"medical_conditions":118,"animal_species":124},1622,"lh2cq47h6jfdn465rds72mq1","methimazole","Methimazole",null,[13],"feline",[15],{"source":16,"licence":17,"source_url":18,"harvested_by":19,"retrieved_at":20},"FDA Green Book","US public domain","https:\u002F\u002Fanimaldrugsatfda.fda.gov\u002Fadafda\u002Fapp\u002Fsearch\u002Fpublic\u002FingredientsInformationExcel\u002FSection2ActiveIngredients","load-reference-corpus.cjs","2026-09-07",[22,28,32,37],{"id":23,"dose_text":24,"species":25,"administration_route":26,"limitation":11,"source_label":27},11138,"The starting dose of Methimazole Coated Tablets is 2.5 mg administered every 12 hours. Following 3 weeks of treatment, the dose should be titrated to effect based on individual serum total T4 (TT4) levels and clinical response. Dose adjustments should be made in 2.5 mg increments. The maximum total dosage is 20 mg per day divided, not to exceed 10 mg as a single administration.","Cats","Oral","Methimazole Coated Tablets",{"id":29,"dose_text":30,"species":25,"administration_route":26,"limitation":11,"source_label":31},11139,"Administer a starting dose of 2.5 mg every 12 hours. Following 3 weeks of treatment, the dose should be titrated to effect based on individual serum total T4 (TT4) levels and clinical response. Dose adjustments should be made in 2.5 mg increments with a maximum dosage of 20 mg per day divided, not to exceed 10 mg as a single dose.","Methimazole Oral Solution",{"id":33,"dose_text":34,"species":11,"administration_route":35,"limitation":11,"source_label":36},11140,"Always include the Instructions for Preparing a Dose of Felanorm (methimazole) Oral Solution and the Information for Cat Owners with the prescription. The starting dose of Felanorm is 2.5 mg administered every 12 hours. Following 3 weeks of treatment, the dose should be titrated to effect based on individual serum total T4 (TT4) levels and clinical response. Dose adjustments should be made in 2.5 mg increments. The maximum total dosage is 20 mg per day divided, not to exceed 10 mg as a single administration.\nHematology, biochemistry, and TT4 should be evaluated prior to initiating treatment and monitored after 3 weeks and 6 weeks of treatment. Thereafter, bloodwork should be monitored every 3 months and the dose adjusted as necessary. Cats receiving doses greater than 10 mg per day should be monitored more frequently.\nThe product should be administered orally using the enclosed graduated dosing syringe. The syringe has measurements representing the mg dose of the product. Rinse\u002Fclean the oral dosing syringe between uses. (See the Instructions for Preparing a Dose of Felanorm (methimazole) Oral Solution).","ORAL","Felanorm® (methimazole) Oral Solution",{"id":38,"dose_text":39,"species":11,"administration_route":35,"limitation":11,"source_label":40},11141,"DOSAGE AND ADMINISTRATION:\nThe starting dose of Felimazole Coated Tablets is 2.5 mg administered every 12 hours. Following 3 weeks of treatment, the dose should be titrated to effect based on individual serum total T4 (TT4) levels and clinical response. Dose adjustments should be made in 2.5 mg increments. The maximum total dosage is 20 mg per day divided, not to exceed 10 mg as a single administration.\nHematology, biochemistry, and TT4 should be evaluated prior to initiating treatment and monitored after 3 weeks and 6 weeks of treatment. Thereafter, bloodwork should be monitored every 3 months and the dose adjusted as necessary. Cats receiving doses greater than 10 mg per day should be monitored more frequently.","Felimazole® Coated Tablets (methimazole tablets)",[42,47,51,53],{"id":43,"strength_text":44,"dosage_form":45,"proprietary_name":46,"species":25,"source_label":46},9772,"5 mg\u002FmL","Oral Solution","Felanorm®",{"id":48,"strength_text":49,"dosage_form":50,"proprietary_name":27,"species":25,"source_label":27},9773,"2.5 mg or 5 mg methimazole per tablet","Coated Tablets",{"id":52,"strength_text":44,"dosage_form":45,"proprietary_name":31,"species":25,"source_label":31},9774,{"id":54,"strength_text":55,"dosage_form":11,"proprietary_name":11,"species":11,"source_label":36},9775,"5 mg \u002F 1 mL",[57,61,66,69,72,76,80,83,87,91,94,97,101,105,108],{"id":58,"kind":59,"statement":60,"species":25,"limitation":11,"source_label":31},16029,"indication","Methimazole Oral Solution is indicated for the treatment of hyperthyroidism in cats.",{"id":62,"kind":59,"statement":63,"species":25,"limitation":64,"source_label":65},16030,"For the treatment of hyperthyroidism in cats.","Due to potentially serious adverse reactions such as hepatopathy, immune-mediated anemia, thrombocytopenia, and agranulocytosis, cats on methimazole therapy should be monitored closely for any sign of illness including anorexia, vomiting, head\u002Ffacial pruritus or edema, depression\u002Flethargy, weight loss, anemia, skin lesions, diarrhea, fever, or lymphadenopathy. If a cat becomes ill while on FELIMAZOLE Coated Tablets, the drug should be stopped and appropriate hematological and biochemical testing should be done (see ANIMAL SAFETY and POST APPROVAL EXPERIENCE).","Felimazole®",{"id":67,"kind":59,"statement":68,"species":11,"limitation":11,"source_label":40},16031,"INDICATION:\nFelimazole Coated Tablets (methimazole tablets) are indicated for the treatment of hyperthyroidism in cats.",{"id":70,"kind":59,"statement":71,"species":11,"limitation":11,"source_label":36},16032,"Felanorm (methimazole) is indicated for the treatment of hyperthyroidism in cats.",{"id":73,"kind":74,"statement":75,"species":11,"limitation":11,"source_label":40},16033,"contraindication","CONTRAINDICATIONS:\nDo not use in cats with hypersensitivity to methimazole, carbimazole or the excipient, polyethylene glycol.\nDo not use in cats with primary liver disease or renal failure.\nDo not use in cats with autoimmune disease. See ADVERSE REACTIONS.\nDo not use in cats with hematological disorders (such as anemia, neutropenia, lymphopenia, or thrombocytopenia) or coagulopathies. See ADVERSE REACTIONS.\nDo not use in pregnant or lactating queens. Laboratory studies in rats and mice have shown evidence of teratogenic and embryotoxic effects of methimazole.",{"id":77,"kind":78,"statement":79,"species":11,"limitation":11,"source_label":36},16034,"warning","Not for use in humans. Keep out of reach of children. For use in cats only. Wear protective single use, impermeable (e.g., latex or nitrile) gloves when administering the solution. Wash hands with soap and water after administration to avoid exposure to drug. Wear protective gloves to prevent direct contact with litter, feces, urine, or vomit of treated cats, and the solution. Wash hands after contact with the litter of treated cats.\nMethimazole is a human teratogen and crosses the placenta concentrating in the fetal thyroid gland. There is also a high rate of transfer into breast milk. Pregnant women or women who may become pregnant, and nursing mothers should wear gloves when handling the solution, litter or bodily fluids of treated cats. Individuals with an endocrine disorder that could be impacted by methimazole should use similar precautions.\nMethimazole may cause vomiting, gastric distress, headache, fever, arthralgia, pruritus, and pancytopenia. In the event of accidental ingestion\u002Foverdose, seek medical advice immediately and show the product label to the physician.\nAvoid skin and oral exposure, including hand-to-mouth contact. Wash any spillages or splatter from the skin immediately. Do not eat, drink, smoke\u002Fvape, or use smokeless tobacco while handling the product or used litter.\nFelanorm may cause skin or eye irritation. Avoid eye contact, including hand-to-eye contact. In case of accidental eye contact, rinse eyes immediately with clean running water. If irritation develops, seek medical advice.",{"id":81,"kind":78,"statement":82,"species":11,"limitation":11,"source_label":40},16035,"HUMAN WARNINGS:\nNot for use in humans. Keep out of reach of children. For use in cats only. Wash hands with soap and water after administration to avoid exposure to drug. Do not break or crush tablets. Wear protective gloves to prevent direct contact with litter, feces, urine, or vomit of treated cats, and broken or moistened tablets. Wash hands after contact with the litter of treated cats.\nMethimazole is a human teratogen and crosses the placenta concentrating in the fetal thyroid gland. There is also a high rate of transfer into breast milk. Pregnant women or women who may become pregnant, and nursing mothers should wear gloves when handling tablets, litter or bodily fluids of treated cats.\nMethimazole may cause vomiting, gastric distress, headache, fever, arthralgia, pruritus, and pancytopenia. In the event of accidental ingestion\u002Foverdose, seek medical advice immediately and show the product label to the physician.",{"id":84,"kind":78,"statement":85,"species":11,"limitation":11,"source_label":86},16036,"Methimazole has anti-vitamin K activity and may induce bleeding diathesis without evidence of thrombocytopenia. See ADVERSE REACTIONS.\nKeep Methimazole Coated Tablets in a secure location out of reach of dogs, cats, and other animals to prevent accidental ingestion or overdose.","Methimazole Coated Tablets (methimazole tablets) For oral use in cats only.",{"id":88,"kind":78,"statement":89,"species":11,"limitation":11,"source_label":90},16037,"Methimazole has anti-vitamin K activity and may induce bleeding diathesis without evidence of thrombocytopenia. See ADVERSE REACTIONS.\nKeep ReguZol Coated Tablets in a secure location out of reach of dogs, cats, and other animals to prevent accidental ingestion or overdose.","ReguZol Coated Tablets (methimazole tablets) For oral use in cats only.",{"id":92,"kind":78,"statement":93,"species":11,"limitation":11,"source_label":36},16038,"Methimazole has anti-vitamin K activity and may induce bleeding diathesis without evidence of thrombocytopenia. See ADVERSE REACTIONS.\nKeep Felanorm in a secure location out of reach of dogs, cats, and other animals to prevent accidental ingestion or overdose.",{"id":95,"kind":78,"statement":96,"species":11,"limitation":11,"source_label":40},16039,"WARNINGS:\nMethimazole has anti-vitamin K activity and may induce bleeding diathesis without evidence of thrombocytopenia. See ADVERSE REACTIONS.",{"id":98,"kind":99,"statement":100,"species":11,"limitation":11,"source_label":86},16040,"adverse_reaction","In a US field study with 113 cats, the most common adverse reactions included change in food consumption (increase or decrease), lethargy, vomiting, diarrhea\u002Floose stool, skin lesions, and abnormal vocalization. Three cats were withdrawn early from the study, one due to unmasking of latent renal disease and two due to the development of skin lesions. Over the course of the study, there was a decreasing trend in the mean counts of red blood cells, lymphocytes, neutrophils and monocytes; however, means remained within or near normal ranges for the testing laboratory.\nIn the extended use phase of the US field study with 101 cats, the most common adverse reactions reported in the study above (lethargy, anorexia) were also observed. Additional signs occurring more frequently in the long-term study were: depression\u002Fwithdrawn behavior, weight loss, haircoat abnormalities, increased blood urea nitrogen (BUN), weakness, agitation and diarrhea. Most of the adverse reactions reported were mild and transient.\nSerum chemistry and hematology results in the extended use study were consistent with the trends noted during the field study. The mean alanine transaminase (ALT) was above the reference range at the first two quarterly visits, but within the normal reference range (10-100 U\u002FL) through the next two quarterly visits.\nMean lymphocyte counts decreased consistently during the study period, to slightly below the reference range (1200-8000 cells\u002FmcL) at the fourth quarterly visit.\nSixteen cats experienced elevated antinuclear antibody (ANA) titers at one or more points during long-term therapy with methimazole tablets but the significance was not determined. Eighteen cats died or were euthanized during the extended use study, four of which may have been related to methimazole tablets due to the unmasking\u002Facceleration of chronic renal failure. See PRECAUTIONS.\nIn a foreign field study with 26 cats using a starting dose of 5 mg twice daily (twice the recommended starting dose), one cat was withdrawn due to lethargy, vomiting and facial excoriations. Marked thrombocytopenia was reported in two cats; the platelet count returned to normal in one cat when methimazole tablets were discontinued. Two cats collapsed and died within 12 days of starting methimazole tablets at a dose of 5 mg twice daily. Both cats were reported with lethargy, vomiting, anorexia, and bloody diarrhea; one cat also had pallor.\nIn a second foreign field study with 78 cats using a starting dose of 2.5 mg twice daily, 4 cats were withdrawn due to suspected adverse reactions to methimazole tablets including anemia, cholangiohepatitis, excoriations, vomiting, lethargy, jaundice, and anorexia. One cat receiving 2.5 mg three times daily collapsed and died after 8 weeks of treatment. Adverse reactions included pallor, anorexia, dehydration, jaundice, bleeding diathesis, and anemia. The most frequently reported adverse reactions included mild, transient, self-limiting vomiting, lethargy, and anorexia.\nForeign Market Experience: The following events were reported voluntarily during post-approval use of methimazole tablets in foreign markets: facial pruritus, self-induced excoriations of the head and neck, generalized lymphadenopathy, thrombocytopenia, hematemesis, epistaxis, and elevation of serum liver enzymes and bilirubin.\nIf overdosage occurs, stop treatment and give symptomatic and supportive care.",{"id":102,"kind":103,"statement":104,"species":11,"limitation":11,"source_label":86},16041,"mechanism_of_action","Methimazole is an antithyroid drug that acts by blocking the biosynthesis of thyroid hormone in vivo. The primary action is to inhibit binding of iodide to the enzyme thyroid peroxidase, thereby preventing the catalyzed iodination of thyroglobulin and T3 and T4 synthesis.\nMethimazole Coated Tablets (methimazole tablets) are well absorbed following oral administration. Maximum plasma concentrations are achieved within 1-1½ hours after dosing and methimazole is rapidly eliminated from the blood (T½ is approximately 3 hours). Administration of Methimazole Coated Tablets in a fasted state enhances absorption.",{"id":106,"kind":103,"statement":107,"species":11,"limitation":11,"source_label":90},16042,"Methimazole is an antithyroid drug that acts by blocking the biosynthesis of thyroid hormone in vivo. The primary action is to inhibit binding of iodide to the enzyme thyroid peroxidase, thereby preventing the catalyzed iodination of thyroglobulin and T3 and T4 synthesis.\nReguZol Coated Tablets (methimazole tablets) are well absorbed following oral administration. Maximum plasma concentrations are achieved within 1-1½ hours after dosing and methimazole is rapidly eliminated from the blood (T½ is approximately 3 hours). Administration of ReguZol Coated Tablets in a fasted state enhances absorption.",{"id":109,"kind":103,"statement":110,"species":11,"limitation":11,"source_label":36},16043,"Methimazole is an antithyroid drug that acts by blocking the biosynthesis of thyroid hormone in vivo. The primary action is to inhibit binding of iodide to the enzyme thyroid peroxidase, thereby preventing the catalyzed iodination of thyroglobulin and T3 and T4 synthesis.\nMethimazole is well absorbed following oral administration. Maximum plasma concentrations are achieved within 1-1 1\u002F2 hours after dosing and methimazole is rapidly eliminated from the blood (T1\u002F2 is approximately 3 hours). Administration of methimazole in a fasted state enhances absorption.",[112],{"id":113,"documentId":114,"slug":115,"name":116},896,"ur0qcpsdwjsa4803iui8bd6z","thyroid-hormone-synthesis-inhibitors","Thyroid Hormone Synthesis Inhibitors",[],[119],{"id":120,"documentId":121,"slug":122,"title":123},96,"hmt4qgnggo33ma2lny55rkmq","hyperthyroidism","Hyperthyroidism",[125],{"id":126,"documentId":127,"slug":128,"name_en":129,"name_ar":11},1426,"j7o7tp1w2784juwb4te34z5r","domestic-cat","Domestic cat"]